William Brangham:

David Prerau has written two books on the strange history of why we change our clocks. It started after the Germans changed their clocks during World War I to save energy. The U.S. later copied that and kept it up for several decades.

In the 1960s, President Johnson signed a law setting official dates for the switching back and forth. But during an energy crisis in the ’70s, President Nixon reversed that, establishing a year-round daylight saving time.

But pretty soon the country saw the darker side of daylight saving, which adds more sunshine to our evening, but steals it from the morning.